Just cracked the case on my 1998 YZ400 last friday. The semi-circular crack is above the top portion of the shaft seal. I came out of a turn and heard a slight crunch and looked down to see oil pouring out of the gearbox. The engine was running fine when I shut the bike off so I'm not certain if damage was done to the motor. I did find a piece of shredded metal laying in the skidplate which looks like it came from the opening. The shaft is now loose, but it feels like all of the gears are still there when I move the shift pedal. Does anyone have experience with this type of break? I realize that the bike is fairly old but would like to salvage as much money out of it as I can. I heard that the case can be welded if you know what you are doing, but that still leaves the transmission to deal with. Any suggestions? Fix or part it out?